Synthesis of Atomically Thin WO₃ Sheets from Hydrated Tungsten Trioxide

Abstract

Synthesis of Atomically Thin WO 3 Sheets from Hydrated Tungsten Trioxide. -Nanosheets of atomically thin WO3 layers are prepared by mechanical exfoliation of WO3·2H2O (obtained from pieces of tungsten foil in HNO3 at 80°C for 6 h) using a piece of an adhesive tape, followed by annealing at 300°C. The samples are characterized by XRD, SEM, TEM, and AFM. The sheets have thicknesses that are multiples of the unit cell height (about 1.4 nm). Raman spectroscopy demonstrates that thinning of WO3 significantly affects physical and chemical behavior. Li intercalation causes significant changes in the Raman spectra for thin samples. The prepared sheets may have great potential in developing two-dimensional electronic and photonic devices such as planar photodiodes and transistors. -(KALANTAR-ZADEH*, K.; VIJAYARAGHAVAN, A.; HAM, M.-H.; ZHENG, H.; BREEDON, M.; STRANO, M. S.; Chem.

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